1. Field of the invention:
The present invention relates to a printer which forms a printing surface by heating a base sheet coated with a lipophilic thermal film, applies a liquid ink to the printing surface, and presses a recording medium against the printing surface to transfer an inked image to the recording medium and, more particularly, to a printer capable of simply and continuously making a dry planographic printing plate in a short time by means of electric signals without requiring any lineal drawing, and capable of continuously performing a printing operation through a step of applying a liquid ink to the planographic printing plate to form an inked image and a step of pressing a recording medium against the planographic printing plate to transfer the inked image to a recording medium.
2. Description of the Related Art:
Printers used as the output equipments of information processing systems are classified roughly into impact printers and nonimpact printers. Recently, demand for nonimpact printers, which are capable of operating silently, printing pictures and graphs and high extendability, has increased greatly. Typical nonimpact printers are electrophotographic printers using toner as a visible image forming medium, ink-jet printers which jet ink particles electrostatically and thermal printers which use a fusible or sublimable thermal transfer ribbon.
The accessibility of the printer is dependent on facility in handling consumable articles, such as toner, ink, ribbons and recording sheets. That is, toner which is liable to scatter, ink which is liable to spill, the transfer ribbon having difficulty in printing in natural color, thermal print papers having difficulty in multicolor printing, and recording sheets having trouble with electrostatic charging, blotting and smoothness are principal factors adversely affecting the accessibility of the printer. Accordingly, those consumable articles also are required to meet specific quality conditions. Furthermore, in addition to accessibility, capability of printing in natural color in satisfactory print quality and capability of printing on ordinary paper sheets are principal demands on the printer. Particularly, the printer is required to be able to print in a print quality equal to that of prints printed with a traditional printing plate. Thermal printers are evaluated favorably in respect of accessibility.
However, the preparation of a conventional printing plate requires many steps of processing a plate, such as a zinc plate, aluminum plate or a plastic plate, including drawing, transferring, engraving, cutting, forming a photosensitive film over the plate, optical exposure, developing, etching and/or rubber application. The photographic plate making process, in particular, includes chemical processes, such as washing and etching. Accordingly, it has been difficult to construct a single compact printer capable of carrying out the photographic plate making process and the printing process.